Each attribute entry must be entered on its own line.
Attributes can be placed in any order in the header, including above the page title.
However, the preferred placement is below the title.
The header can also contain comments.

Page title

A page title is specified by one equals sign (=), followed by one blank space, and then the text of the title.

Page title syntax

= The title of this page

Page metadata

Author syntax

Specifying the author or authors of a page is optional.
The author is listed on the line directly beneath the page’s title.
An optional email address or contact URL can follow an author’s name inside a set of angle brackets (< >).
When a page has multiple authors, each author is separated by a semicolon (;).

Multiple authors and author information syntax

= Page Title
First Middle Last <author@email.com>; First Last <author@email.com>

Page attributes are set in the header and are available to the whole page.
Built-in AsciiDoc attributes are reserved attributes that have special, pre-defined behavior.
Many built-in attributes also have a restricted set of accepted values.

Built-in page attributes usually do two things; they toggle a behavior on or off (boolean), and they change the generated output by accepting an alternate value or replacement content (variable).

Set and unset built-in attributes

Let’s turn on the attribute sectanchors.

Set a built-in page attribute

= Page Title
:sectanchors:

When turned on, sectanchors adds an anchor to the left of each section title.
The anchor is rendered as the symbol §.
The attribute is turned on, also known as set, by simply entering it into the header.

Built-in attributes that are on by default, like table-captions, can be unset (turned off) with a leading or trailing ! added to its name.

Unset a built-in page attribute

= Page Title
:sectanchors:
:table-caption!:

Change a built-in attribute value

Let’s look at an example of a built-in attribute that has a default value that we want to replace with a custom value.

The label on a Note admonition is controlled by the attribute note-caption.
This attribute is set (on) by default and has an implicit value of NOTE.
Let’s change the value to “OPS HINT”.

Change a built-in page attribute value

= Page Title
:note-caption: OPS HINT

Now, when we create a Note admonition, its label is displayed as OPS HINT.